The average weekly number of robots produced by Factory D and E is 3249. The average weekly number of robots produced by Factory D and F is 6209. If Factory E produced ⁴₉ as many robots as Factory F each week, how many robots does Factory D produce weekly?
Total robots that Factory D and Factory E produced
= 3249 x 2
= 6498

Total robots that Factory D and Factory F produced
= 6209 x 2
= 12418

Number of robots produced by Factory E = 4 u
Number of robots produced by Factory F = 9 u

Factory D's toys + 4 u = 6498 --- (1)
Factory D's toys + 9 u = 12418 --- (2)

(2) - (1)
9 u - 4 u = 12418 - 6498
5 u = 5920
1 u = 5920 ÷ 5 = 1184

Number of robots produced by E
= 4 u
= 4 x 1184
= 4736

Number of robots produced by D
= 6498 - 4736
= 1762

Answer(s): 1762